[1] Univ Heidelberg, Dept Med Gastroenterol Hepatol & Infect Dis 2, D-6800 Mannheim, Germany
[2] Tech Univ Munich, Dept Surg, Munich, Germany
[3] Charite, CCM, Dept Gastroenterol Hepatol & Endocrinol, D-13353 Berlin, Germany
[4] Charite, Charite Campus Virchow, Dept Gastroenterol & Hepatol, D-13353 Berlin, Germany
[5] Univ Leipzig, Dept Gastroenterol & Hepatol, Leipzig, Germany
[6] Otto von Guericke Univ, Dept Surg, Magdeburg, Germany
[7] Univ Marburg, Dept Gastroenterol, Marburg, Germany
[8] Helsinki Univ Cent Hosp, Dept Surg, Helsinki, Finland